Free convection around human bodies with diverse shapes*

Excessive indoor warmth can harm health and productivity, especially during heat waves or in buildings without air conditioning. Designing energy-efficient buildings that provide thermal comfort for diverse populations can reduce such negative health impacts, but it requires a quantitative understanding of the main heat exchange pathways—radiation and free convection—between humans and their indoor environment. Traditional methods to quantify these heat exchange pathways involved human subjects but were time-consuming and variable. Modern studies use physical or computational human models ("manikins"), but only when representing the shape of the "average" Western person. We address this gap by employing an experimentally validated numerical model to determine whole-body and regional free convection coefficients across diverse body shapes. We validate the simulations using a thermal manikin, ANDI, and simulate free convection around computational manikins representing the 1st to 99th percentile body mass index and height variations in U.S. adults.